Safety-lock for incandescent lamps



(No Model.) 4

E. PALLER 85H. HERBSTRITT. SAFETY LOOK FOR INOANDESGENT LAMPS.

No. 605,279. Patented June '7, 1898.

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Nrrnn STATES Afr nNT Frrcn.

ERNST FALLER AND I-IERRMANN HERBSTRITT, OF SAN FRANCISCO,

. CALIFORNIA.

SAFETY-LOCK FOR INQA ND ESCENT LAMPS.

v SPECIFICATION forming part of Letters Patent No. 605,279, dated June 7, 1898.

Application filed. $eptembcr 17, 1897. Serial No. 651,988. (No model.)

To all whom it may concern;

Be it known that we, ERNST, FALLER and HERRMANN Hnnnsrnrrr, citizens of Germany,

residing in the city and county of- San Fran- It consists of the parts and the constructions and combinations of parts hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a view showing the globe in its position. Fig.

- 2 is a transverse section through the locking device. Fig. 3 is an exterior detail view of the same. I

In the employment of the incandescentlight globes it is customary to screw these globes in to the permanent sockets with which the wires connect, where the proper contacts are made, so that by turning the key the elec-' trical current will pass through the filament and produce the light, which may be closed off in the same manner. Considerable difticulty and annoyance have resulted from the ease with which these globes can be disengaged from the permanent socket, and they are very often stolen or removed, so that it is necessary to supply the loss with new ones. Our, device is intended to prevent this surreptif tious removal and to lock the globes in place, so that they cannot be removed as long as they are in operative condition.

A is a globe of an incandescentlamp, having the usual metallic threaded portion B permanently attached to it. This threaded portion B is adaptedtoscrew into the corresponding threaded socket 0, formed within the permanent fixturev D, and when thus screwed in until contact is made with the proper contact-points within the permanent fixtureit is in condition for use.

In this invention we have devised a look by which the globe can be permanently retained when once introduced, so that it cannot be again removed until the globe is broken. In forming this look various devices may be employed. As here shown, a depression is made in one of the threads of the screw portion 13, forming a shoulder, as shown at a. Upon the interior of the socket portion is formed a tongue b,which in the present case is formed.

by cutting away a portion of one of the screwthreads of this socket portion and forming a point of the projecting strip 0, which is suiticiently elastic, so that this point may be normally caused to press inwardly against the eggterior of the screw-threaded portion B.

The operation will then be as follows:

When the globe is to be connected with the fixture, the screw-threaded portion 13 is introduced into the corresponding screw-threaded portion of the fixture and it is turned around until it reaches the point of contact, when it is ready for lighting. At this instant the tongue drops in behind'the notch or catch a and thus prevents the globe from being again turned in the reverse direction. As the latch and catch are concealed within the exterior portion of the fixture, it is not possible to tallic portion B to indicate the exact point where the latch is located, so that after the glass has been broken the metal can be depressed at this point to disengage the catch. Having thus described our inventiomwhat we claim as new, and desire to secure by Let ters Patent, is-

1. Anincandescent-light globe having a metallic end adapted to engage with thecorresponding portion of the permanent fixture, a catch formed in one of theengaging parts and 'a corresponding automatically-engaging tongue upon the other, said tongue projecting inwardly whereby it is concealed Within catch formed upon the entering interlocking portion, and an elastic automatically-engaging tongue projecting inwardly from the other portion of the fixture so that it can only be reached from the interior of said end or base whereby the two are engaged and permanently locked when the globe is in position I5 for operation.

In witness whereof we have hereunto set our hands.

ERNST FALLER. HERRMANN .I-IERBSTRITT.

Witnesses:

S. H. NOURSE, JEssIE O. BRQDIE. 

